nodejs不需要登陆的验证码

npm install canvas nodemailer

const express = require('express');
const Canvas = require('canvas');
const nodemailer = require('nodemailer');

const app = express();
const PORT = process.env.PORT || 3000;
const WIDTH = 100;
const HEIGHT = 50;

// 生成随机字符串
const randomString = () => {
  const CHARACTERS = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
  let result = '';
  for (let i = 0; i < 6; i++) {
    result += CHARACTERS.charAt(Math.floor(Math.random() * CHARACTERS.length));
  }
  return result;
};

// 生成验证码图片
const generateCaptcha = () => {
  const canvas = Canvas.createCanvas(WIDTH, HEIGHT);
  const ctx = canvas.getContext('2d');
  const captcha = randomString();
  ctx.clearRect(0, 0, WIDTH, HEIGHT);
  ctx.font = 'bold 25px sans-serif';
  ctx.fillStyle = '#333';
  ctx.fillText(captcha, 20, 35);
  return { captcha, dataURL: canvas.toDataURL() };
};

// 初始化缓存
const cache = {};

app.use(express.static('public'));

// 根路由返回验证码图片
app.get('/', (req, res) => {
  const captcha = generateCaptcha();
  cache[captcha.captcha] = true;
  res.send(`<img src="${captcha.dataURL}">`);
});

// 验证码验证路由
app.get('/captcha', (req, res) => {
  const { captcha } = req.query;
  if (captcha && cache[captcha]) {
    delete cache[captcha];
    res.send({ success: true });
  } else {
    res.send({ success: false });
  }
});

// 发送邮件路由
app.get('/email', (req, res) => {
  const { email } = req.query;
  if (email) {
    const captcha = generateCaptcha();
    cache[captcha.captcha] = email;
    const transporter = nodemailer.createTransport({
      host: 'smtp.ethereal.email',
      port: 587,
      secure: false,
      auth: {
        user: testAccount.user,
        pass: testAccount.pass
      }
    });
    const message = {
      from: 'nodejs-captcha@example.com',
      to: email,
      subject: '验证码',
      text: captcha.captcha,
      html: `<img src="${captcha.dataURL}">`
    };
    transporter.sendMail(message, (err, info) => {
      if (err) {
        console.log(err);
        res.send({ success: false });
      } else {
        console.log(info);
        res.send({ success: true });
      }
    });
  } else {
    res.send({ success: false });
  }
});

app.listen(PORT, () => {
  console.log(`Server is running on port ${PORT}`);
});